Question

Let f be the function that determines the area of a circle (in square cm) that has a radius of r cm. That is, f ( r ) represents the area of a circle (in square cm) that has a radius of r cm.Use function notation to complete the following tasks

a. Represent the area (in square cm) of a circle whose radius is 4 cm.
b. Represent how much the area (in square cm) of a circle increases by when its radius increases from 10.9 to 10.91 cm.

Answer 1

(a)f(4) square cm.

(b)f(10.91)-f(10.9) Square centimeter.

Explanation:

f(r)=the area of a circle (in square cm) that has a radius of r cm.

(a)Area (in square cm) of a circle whose radius is 4 cm.

Since r=4cm

Area of the circle = f(4) square cm.

(b) When the radius of the increases from 10.9 to 10.91 cm.

• Area of the circle with a radius of 10.91 = f(10.91) square cm.
• Area of the circle with a radius of 10.9 = f(10.9) square cm.

Change in the Area = f(10.91)-f(10.9) Square centimeter.